It is known to stamp sheet metal blanks to form a spring retainer for a torsional vibration damper. To form the pockets that will hold the springs for the damper, the radially outermost portion of the blank must be curled over itself toward a center of the blank. However, the opening to the pocket must be reduced such that it is not possible to support the lower side of the outermost portion as the upper side is pushed and pressed by a die to perform the curling. Due to this lack of support, the curled portion may not attain the desired curvature and undesirable flattening, kinking, or other distortion may occur. In addition, the repeatability of the curling operation is compromised.